1. Field of the Invention
The invention relates to an apparatus for the injection of corrosion or other inhibitor, or gas for artificial lift purposes, utilizing an apparatus having a packer assembly concentrically receiving parallel fluid flow conduits extending above the packer assembly, the packer assembly having selectively activatable hold-down buttons, or casing gripping means, which may be activated by pressure defined through the fluid carried through one of the fluid flow conduits from the top of the well.
2. Description of the Prior Art
During the production of a subterranean oil well, it may be necessary to artifically lift the production fluid from the production zone, because the pressure within the well is insufficient to transmit the produced fluids to the top of the well, without auxiliary or artificial lift means. In such instances, gas is selectively injected into the well by means of a conventionally activated valve apparatus carried within a side pocket mandrel on a fluid flow conduit for injection into or slightly below the zone to urge the production fluid to the top of the well through a production string. The gas may be injected into the valve through the annular area between the tubing and the casing. Alternatively, a "short" or "injection" string may extend from the top of the well to the production zone, without incorporation of the valve and side pocket mandrel.
During the production of a subterranean well, in many instances, it will be desirable to inject a corrosion or other inhibitor with the produced fluid to prevent corrosion to component parts of the completion and production assembly within the well. Such inhibitor generally is injected to the production zone through a "short" tubing string, or through the tubing-casing annulus for injection through a packer assembly sealingly engaged within the casing and above the production zone, thence through the lowermost exterior end of the packer, and with the production fluid through the production or "long" string, to the top of the well.
The utilization of parallel tubing strings through a packer assembly of necessity reduces the diameter of each string, and adversely affects the carriable production volume of the production or "long" string. Therefore, it would be most desirable for parallel tubing strings to become concentrically mounted through the packer assembly, in order to afford maximum internal diameter for the production string.
The present invention provides such concentric mounting of the tubing strings within a packer assembly, and also provides selectively activatable casing gripping means to assure sealing engagement of the packer apparatus in the bore of the well above the production zone. Additionally, the present invention provides a packer assembly which comprises casing gripping, selectively activatable, fluid responsive hold-down buttons which may themselves be activated into gripping engagement with the casing by transmission of the inhibitor or other fluid through the concentrically mounted tubing strings within the packer assembly, from the top of the well.